/Engine/Source/Runtime/Landscape/Classes/LandscapeProxy.h
Output a landscape heightmap to a render target
bool LandscapeExportHeightmapToRenderTarget ( [UTextureRenderTarget2D](API\Runtime\Engine\Engine\UTextureRenderTarget2D) * InRenderTarget, bool InExportHeightIntoRGChannel, bool InExportLandscapeProxies )